The present invention relates to a clamping apparatus comprising a chuck member and a pallet member adapted to be releasably fixed to the chuck member. The chuck member has at least three centering grooves, and the pallet member has a corresponding number of centering pins arranged and shaped to correspond to the centering grooves. The chuck member further comprises clamping means for clamping the pallet to the chuck member.
Clamping apparatuses of the kind mentioned above are mainly used to fix work pieces in a positionally well defined manner in the machining area of a machine tool. Thereby, the work piece first is fixed to a pallet and the pallet is to be releasably attached to the chuck member. In most cases, the chuck member itself is fixedly attached to the machine tool.
In known clamping apparatuses of this kind, usually the chuck member is provided with four centering pins, each having two opposed, conically shaped side surfaces. The pallet is provided with four grooves, corresponding in location and shape to the afore mentioned centering pins. The pallet comprises a centrally located clamping bar by means of which it can be clampingly fixed to the chuck member. Upon clampingly fixing the pallet to the chuck member, the centering pins enter the centering grooves and align the pallet with regard to the chuck member in X- and Y-directions as well as with regard to its angular position.